This application is based on and claims Convention priority to Japanese patent application No. 2009-205822, filed Sep. 7, 2009, the entire disclosure of which is herein incorporated by reference as a part of this application.
The present invention relates to an X-ray fluorescence analyzing method utilizing a so-called scattered X-rays internal standard method.
In the field of X-ray fluorescence analysis, such a method has hitherto been available, in which in determining the content of a metal (an element to be analyzed) contained in, for example, a mineral sample, the ratio between the intensity of fluorescent X-rays, emitted from the element to be analyzed, and the intensity of Compton scattering X-rays of characteristic X-rays of primary X-rays is utilized in order to minimize inter-element effect on the absorption of the fluorescent X-rays emitted from the element to be analyzed. (See the Patent Documents 1 and 2 listed below.) This known method is known as a scattered X-rays internal standard method, in which as internal standard lines the Compton scattering X-rays of the characteristic X-rays of the primary X-rays are utilized. In such case, it has been well known that that the intensity of the Compton scattering X-rays of the characteristic X-rays of the primary X-rays is approximately inversely proportional to the mass absorption coefficient relative to the fluorescent X-rays emitted from the element to be analyzed means that such Compton scattering X-rays are effective as the internal standard line. (See the Non-patent Document 1 listed below.) Also, another method is currently available, in which for the internal standard line, a background in a vicinity of a wavelength of an analytical line, that is, scattered X-rays of a wavelength near the spectrum of the fluorescent X-rays of the element to be analyzed is utilized. (See the Patent Documents 2 and 3 listed below.)                [Patent Document 1] JP Laid-open Patent Publication No. H10-82749 (See Paras. [0037] to [0040])        [Patent Document 2] JP Patent Publication No. 3569734 (See Paras. [0039], [0036] and [0075])        [Patent Document 3] JP Laid-open Patent Publication No. 2008-298679 (See paras. [0001] to [0005] and [0024])        [Non-patent Document 1] Yoshiyuki Kataoka, et al., “Doseiren ni Okeru Keiko X-sen Bunseki”, Advances in X-ray Chemical Analysis, 1981, Vol. 13, p. 145-152.        [Non-patent Document 2] Rigaku Denki Kogyo Kabushiki Kaisha, Oyo Gijutsu Center (Applied Technology Center), “Keiko X-sen Bunseki Jisshu Tekisuto (Text for Exercise in X-ray Fluorescence Analysis)”, First print of 4-th edition, Rigaku Denki Kogyo Kabushiki Kaisha, February, 1997, p. 37        
It has, however, been found that if an attempt is made to determine the concentration (content) of sulfur (an element to be analyzed, which has the atomic number ranging from 9 to 20) contained in, for example, oil relative to a liquid sample such as, for example, oils, organic solvent or aqueous solution, that is, a liquid sample containing, as a principal component, hydrogen and at least one element selected from the group consisting of carbon, oxygen and nitrogen (all of which are a so-called non-measurable element of which fluorescent X-rays cannot be measured as a matter of fact) by the application of the above described prior art technology, the concentration of the element to be analyzed cannot be accurately determined because due to the non-measurable elements contained in quantity in the sample, the internal standard line fail to reflect the composition of the sample accurately.